Patent GB-190485-A (GB)
Title: Improvements in controlling means for valves or the like
IPC: F01D17/26
Filed: 1922-12-13
Abstract: 190,485. Aktiebolaget Vaporackumulator. Dec. 14, 1921, [Convention date]. Fluid - actuated valves. - A valve is operated by a piston actuated by fluid pressure under the control of an auxiliary valve which is in turn actuated by a single relay responsive to two or more impulses due to speed, temperature, maximum or minimum pressure, or the like, any one of which may be caused to open or close the valve irrespectively of the tendency of the other impulses. A valve d in a pipe line e is operated by a piston under control of pressure fluid in the space c above, and a spring u below. A pipe q connects the space c with the space p of an auxiliary valve device which contains three chambers k, n, p, separated by partitions through which a plunger s passes. The plunger s and its piston b are under the control of pressure fluid in the space k below, and a spring r above. The space k is connected by a pipe i to a pipe h having an opening v in a relay device a, and a pipe l controlled by a throttle valve connects the spaces k, n. If the opening v is closed, pressure fluid passes through the pipe o, space n and pipe l to the space k and lifts the piston b, thereby allowing pressure fluid to pass into the space p, pipe q, and space c, to open the valve. Conversely, if the opening v is opened by the relay, pressure in the space k is relieved, the piston b falls, thereby allowing pressure fluid in the space p to pass to the outlet t, and the valve d closes. The relay a comprises a plate controlling the opening v, connected to a rod 7 and a plate 5 under the control of various impulses. A speed governor f is adapted to actuate the place 5 from below by means of links 2, 3, 4, and a temperature regulator 8 actuates the plate 5 from above through link 9, sleeve 10, sliding pin 12, and strong spring 11. The spring 6 is much weaker than the springs 11, 16 or 23, so that the relay may be actuated without much compression of the latter. The pressure in front of the valve d may act through a pipe 13 and diaphragm 14, on the upper side of the plate 5, in a similar manner. The pressure behind the valve d may actuate the relay through a pipe 18, diaphragm 19, and rods 20, 21, 24, so that the plate 5 is displaced downwards by a spring 23 on a decrease of pressure in the pipe 18. An increase in pressure on the diaphragm 19 above a predetermined limit, lifts the plate 5 through a lever 26. Since all the impulses acting on the plate 5 from below act through a rigid system, any action of these impulses tending to control the relay will prevail notwithstanding any counter-impulses acting above the plate 5 through the springs 11, 16, 23. Further, any one impulse acting on the plate from above tending to close the opening v and thus open the valve d, will prevail notwithstanding any opposite tendency on the part of other impulses acting above the plate, provided that the impulses acting below the plate are not acting in the opposite direction. The conditions are reversed if the rigidly acting impulses are above the plate 5 and the resilient impulses below. Any other number of impulses or combinations of impulses may be applied in a similar manner. A modified form of relay is shown in Fig. 2, in which the control is such that the valve is opened if either of two pressures tends to open it, but is closed if one pressure reaches a predetermined maximum. The two pressures act on two diaphragms 30, 31 to control a pivoted lever 39 which regulates the opening v. The diaphragm 30 is rigidly connected to a strap 38 by an adjustable screw 37, and the diaphragm 31 bears loosely against a sleeve 32 which actuates a sliding pin 34 against spring 33. Adjustable lostmotion stops 35, 36 are provided. An increase of pressure behind the diaphragm 31 beyond a predetermined limit closes the opening v and consequently opens the valve d; a decrease of pressure behind the diaphragm 30 has a similar effect, and an increase has an opposite effect, the limits being determined by 'the stops 35, 36. Combinations of two or more relays may be used to actuate the valve,